This invention relates generally to ignition systems for internal combustion engines. More particularly, this invention relates to laser ignition systems for internal combustion engines with continuous combustion.
For internal combustion engines, fuel is combusted with an oxidizer (usually air) in combustion chambers. The resulting high temperature and pressure gases expand and thereby apply forces to movable components of the engines, such as turbine blades to drive the turbine. Combustion can be intermittent (as for example, in automotive applications) or continuous (as for example, in gas turbines and jet engines).
In a conventional ignition apparatus for internal combustion engines, a high voltage is applied to an ignition plug that is fixed on a wall surface of the combustion chamber in order to ignite an air-fuel mixture by spark discharge. However, in an ignition apparatus of this kind, since the ignition plug is exposed directly to the combustion chamber, carbon attaches to the ignition plug to render the discharge of the ignition plug difficult. Furthermore, due to a heat loss of the electrodes of the ignition plug, a torch or nucleus of flame generated by the discharge is cooled, and vanishes before reaching a flame. Additionally, since the ignition occurs on or very near the wall surface, poor mixing often results due to the difficulties associated with burning fuel from the wall surface.
Therefore, there is a need for a new and improved ignition system and method for internal combustion engines.